1. Field of the Invention
The present invention relates generally to stereoscopic viewers, and more particularly to an adjustable head mounted stereoscopic viewer using mirrors that accommodates different picture sizes and different viewing distances.
2. Brief Description of the Prior Art
Many different types of stereoscopic viewers have been designed and used over the years. The simplest of these are constructed as a single hand-held binocular device providing illumination and display of left and right image slides to a user's corresponding eyes. These devices provide high quality fixed images to a single viewer. The advent of motion pictures was followed by attempts to display and view this media in stereo. Attempts at this included the display of polarized left and right images viewed with corresponding polarized eye glasses. The quality and comfort of viewing in these applications was less than ideal. An attempt at stereo viewing of television images is described in U.S. Pat. 5,357,369 by Pilling et al., wherein a device is clamped to the screen/monitor. Like the hand held viewer, this apparatus can only be used by one observer at a time, and does not allow the user freedom of movement. An improved device is described in U.S. Pat. No. 4,740,836 by Craig that uses mirrors or prisms to direct left and right television images. This patent describes the devices as mounted in a pair of spectacles, but no disclosure of structure is given, and at this time such a device is not available on the market. Craig also requires the use of polarizers to eliminate unwanted images. The viewers as disclosed by Craig and others in the prior art, do not allow a user to conveniently view stereoscopic images in full color without significant image intensity loss. It is clear from the above description of the prior art that there is a need for a practical, inexpensive stereo viewer which will allow a number of users to view a single stereo image.